Book mark



FIG. 1 is a perspective view of a book mark showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a bottom plan view thereof.

The ornamental design for a book mark, as shown and described.